Safety guard for presses



Nov. 28, 1950 a. F. BEE'BME SAFETY GUARD FOR PRESSES 2 Sheets-Sheet 1Filed Nov. 2, 1948 INVENTOR. BEER BE FBEEBE T TORNE Y Patented Nov. 28,1950 UNITED STATES PATENT OFFICE 2,531,837 SAFETY GUARD roa PRESSESGeorge F. Beebe, Waterbury, Conn.

Application November 2, 1948, Serial N 0. 58,000 '1 Claims. (01.192 13?)This invention relates to new and useful improvements in safety devicesand has particular relation to a guard for machines of the typeincluding a vertically movable plunger although, as herein disclosed,the guard is specifically for a foot operated type of press.

An object of the invention is .to provide a guard for and in a machineof the character indicated and including a feeler means movable inadvance of the machine tool and a lock means for positively locking themachine plunger against downward movement, the former beinginterconnected with the latter in such a manner as to bring aboutlocking of the plunger against complete downward movement or a completedownward stroke on said feeler means contacting an object, as the handor finger of an operator, short of its full movement or its movement towhich it is adapted in the usual safe operation of the machine.

Another object is to provide for and in a machine a safety guard meansmovable downwardly by gravity in advance of the machine plunger andupwardly by the machine plunger on return movement of the latter incombination with means under the control of said feeler means to causestoppage of downward movement of the plunger on said feeler meansengaging an object short of its normal full downward movement.

A further and more specific object is to provide in a machine includinga head having a vertical way therein and a punch carrying plungerreciprocable in said way, a block rigidly attached to said plunger andprojecting forwardly from said way, a mounting plate fixed to said headat one side of said way, a locking cam pivoted to said plate formovement into and out of the path of movement of said block, a pair ofvertically spaced a'rms pivoted each at one end to said plate, a carrierplate spaced horizontally from said mounting plate, means pivoting theother ends of said arms to said carrier plate in the same spacedrelation as the first mentioned ends of the arms are pivoted to themounting plate whereby a pantograph-like structure is provided in whichthe carrier plate is movable in substantially parallel relation with themounting plate, a feeler bar mounted on said carrier'plate and extendingdownwardly therefrom said plunger, means on one of said arms and havinga pin and slot connection with said cam for moving the latter to andfrom the path of said block to release said plunger for downwardmovement and to lock it against downward movement, and a connectionbetween one of said arms and said.

arms move about the pivots at their first men-. tioned ends and said camis moved out of the path of movement of said plunger carried block andwhereby as said plunger and block move upwardly on return movement ofthese parts said carrier plate and feeler rod are returned to theirnormal positions as the arms are rocked back.

on the pivots at their first mentioned ends and on predeterminedmovement of one such arm the pin and slot connection between itsextension and the cam brings the latter back into the path of downwardmovement of said block. 7

Other objects and advantages of the invention will become apparent froma consideration of the following detailed description taken inconnection with the accompanying drawings wherein a satisfactoryembodiment of the invention is shown. However, it is to be understoodthat the invention is not limited to the details disclosed but includesall such variations and modifications as fall within the spirit of theinvention and the scope of the appended claims.

In the drawings:

Fig. l is a side elevational view showing a foot press equipped with thesafety means or guard of the invention;

Fig. 2 is a front elevational viewof said press,

the view being taken as looking from the right in Fig. 1;

Fig. 3 is a front elevational View on a larger showing the parts as whenthe press plunger has been arrested or locked due to engagement of thefingers of an operator by the feeler device of the present safety meansor guard;

Fig. 6 is a somewhat similar view showing the relation of the parts atthe limit of normal downward movement of the press plunger and punch;and

Fig. '7 is an enlarged front elevational view of certain. of the partsshown in Fig. 5.

Referring in detail to the drawings, a kicker 011' foot operated type ofpress is shown and is generally designated l0. Such press comprises abase H supporting an upright l2, the upper forward portion of whichis'laterally enlarged as at 13- providing a, head. Such headis recessedin its forward face and in opposite edge portions of said recess arelocated guides I4 and I5 having V-shaped ways I6 and I1 therein andwhich ways are in opposing relation. The guide I5 is secured in place asby a series of bolts I8 while the guide I4 is also secured in place bythree bolts, one of which, designated I9, passes through the upperportion of the guide and the other two of which are designated and passnot only through the guide but also through a mounting plate 2 I, thepurpose of which will later be set forth. All of these bolts arethreaded into the head portion of the upright I3, as best shown in Fig.4.

Vertically slidable in the ways It and I1 of the guides I4 and I5 is aplunger 22 adapted in its lower end to mount a punch or other tool 23,depending on the job to be performed. As best shown in Fig. 4, theplunger 22 projects forwardly out of the guide way provided for it andas shown in Figs. 1 and 2, at its upper end, the plunger has a rearwardextension or projection 24 through which is threaded .a screw 25comprising an adjustablestop for limiting downward movement of theplunger with respect to the above mentioned head formed on the upperportion of the upright I2.

A tread1e'26 isintegral with or otherwise made rigid with an arm 21shown as having its upper portion curved forwardly as at 28. Inwardly.

of its upper end, arm 21 is pivotally mounted. at 29 on the upright I2and then the forward .end of said arm is, by means of a pin orthe like30, secured to the plunger 22. This forward end of arm 21 I havedesignated 3 I and it will. be noted that the same passes through theplunger-22 as well. as being secured to the latterby the pin or otherpivot 30. With this construction it will be understood, especially withreference to Fig. 1, that on the treadle 26 being rocked downwardly andrearwardly, the arm 21 turns on a pivot .29 whereby the forwardend 3| ofsaid arm moves downwardly carrying the plunger 22 with it.

Downward movement of the plunger will be limited by the screw 25 and/orby the .punch 23 engagin or completing its work. In this connection, adie holder or work supportin block or the like 32 is shown as secured tothe upper side of base II by machine screws 33, such die holder or worksupport being located beneath the punch 23. Base H is shown as in itsopposite edges provided with openings or channels 34 for the passage ofclamps or clampbolts for anchoring the press to anysuitable support. Thepress, as thus far described, is old and well known and is disclosedhere in order that the application and operation of my guard or safetydevice may be better understood- Such guard or safety device includesthe mounting plate 2I previously mentioned. A pivot means. 35 piv'otallysecures one end of an arm of link 36 to the mounting plate 2|,whileapivot means 31 pivotally secures the other end of said arm or link to alower portion of a carrier plate 38.. Fixed to this carrier plate,.inany suitable manner, as by means of a screw 39 is a clamp 40 throughwhich passes a vertically disposed feeler rod 4|. Clearly, on looseningof the screw 39 such feeler rod may be adjusted vertically through theclamp 40 and thereafter on tight- "is also pivoted for free movement.

means 42, here disclosed as a U-shaped means, the arms of which straddlethe punch 23. The position of the U-shaped means is controlled by a locknut 43 adjustable on the lower portion of said feeler rod 4I although,generally speaking, any adjustment made and involvin the feeler rod ismade on loosening and thereafter tightening of the clamp 40 as above setforth.

A second arm 44 is pivotally mounted on the plate 2| by a pivot means 45located in vertically spaced aligned relation with the pivot means 35.Also, a pivot means 46 pivotally secures the other end of the arm 44 tothe carrier plate 38 in aligned vertically spaced relation to the pivotmeans-31. Thus, it will be seen that a pantograph-like structure isformed.

. A notch or recess 41 is formed opening through the forward face andthe inner edge of the mounting plate 2| and such notch or recess is of asize and shape to wholly or substantially wholly receive a cam 48 whensuch cam is in unlocked or released position, as shown in Fig. 6. This.camis mounted on a pivot 45 and includes an upper curved or arcuatesurface 50. Additionally, rigid with the cam and extending forwardlytherefrom is a pin 5I projecting into or through aslot 52 in aplate-like extension 53 of the arm44. vAs here shown, this plate-likeextension and-the .arm 44 are all blanked or otherwise formedfrom asingle piece of metal. Slot52'is somewhat L-shaped .and includes averticaltoe-like portion 54 as well as an arcuate portion55.

.In additionto the extension53 which projects from .theunder .orlowerside of arm 44, thereis integral .with such arm and projecting from theupper side or-edge thereof, adjacent the .end mounted on the pivot45, asecond extension 55 carrying a pin 51 projecting at the inner sideofsaid extension 56. This projecting portion of the pin cooperates withthe horizontal surface 59 atone upper corner of a locking plate 611.secured to the forward side or face of the plunger 22 asby machinescrews 6|. One lower corner of this plate 60 is cutaway providing anarcuate surface 62 on the same length radius as and. for cooperationwith the curved surface 50 of thecam 48,as will be set forth.

When. mounting thepresent guard or-safety device on the press In, it ispreferred to remove the two screws which normally occupy the position ofthe screws-- 20 and then locate the mountingplate by aligning holes init with the screw holes in the guide I4 and then-employing the longerbolts 20 to secure this mounting plate in place. The lock plated!) ispositioned on the plunger .22 in accordance with the location of themounting plate 2|- As-this descriptionproceeds, it willtbecome apparentthat the lockplate E0 is butaportion rigid with the plunger 22 and butfor inconvenience and expense in manufactureand-assembly of a new presscould be anintegral part of the plunger of such new press.

The above described pantograph-like means including the arms Y36 and 44and the carrying plate and the feeler mechanism mounted on. thelatter-are all adapted for pantograph-like movement .on rocking of thearms about the respective pivot means 35 and 45. The cam 48 since thestud or-pin 51 is.rigid withthe arm extension 56, when the plunger 22 ismoved toward itsreturn or upper position, its lower surface 59 engagingthe extension of pin '51 carries the same upwardly therebythrougntheextension 56. rockv 5.1 ing the arm 44 in a clockwisedirection whereby said arm is swung upwardly, as from any of thepositions of Figs. 5, 6 and 7 to the position of Figs. 2 and 3.

This arm being attached to the carrier plate and through its connectionby pivot 31 with arm 36 carries said arm upwardly. Also, this de---scribed upward movement of the plate 38 results in upward or returnmovement of the feeler rod 4|. turn movement of the plunger 22, theparts of the present guard or safety device are given a return movement.Also, it isnoted that since at the end of any return movement theextension of pin 51 will be in engagement with the lock block 60, theparts of the safety device will be held in their upper or return ornormal positions.

In connection with this matter of the return of the parts by the plunger22 on return movement of the latter, it is noted that a channel-orgroove'or elongated corner notch 58 is provided in the forward corner ofthe upper inner edge of the mounting plate 2|. The right hand edge ofthe lock plate 60 is adjacent this inner edge of the mounting plate 2|.Also, the projecting portion of pin 5'! is of a diameter to be receivedin the notch 58 as seen in Figs. 2 and 3. Therefore, on the returnmovement of the plunger 22, the lock plate 88 carried by said plungerthrough its portion 59 engages and raises the pin and the other parts ofthe safety device as previously described. However, since the raisingmovements of the guard parts includes a swinging movement of arm 44 onpivot 45, the pin 51 moves on an arc upwardly and to the right as themachine is shown in front elevation. The parts are movable sufficientlyto have the projecting portion of the pin move entirely into the notch58. This allows for excessive upward movement of the plunger 22 and lockplate 60 without damage to the pin 57 or any other part. When any suchmovement occurs, the pin will be held by a side or vertical edge ofplate 60, rather than by a horizontal or top edge of the latter.

The mentioned return or upper positions are as especially shown in Figs.2 and 3. There it will be noted that the pin 5| of the cam 48 is in thecurved portion 55 of the slot 52 and that such cam is tilted partly outof its pocket or socket 4'! so as to partly project under the lock block50. Specifically, a portion of the curved surface 5!) of the cam isbelow and in alignment with a portion of the curved surface 62 of thelock block. The slot portion 55 is shown as somewhat excessive in lengthto allow for a greater return movement of the plunger than that hereillustrated should such return movement be desired.

'The plunger 22 being in its upper position, the operator will place apiece of work on the holder 32 and then operate the lever 21 to depressthe plunger and bring the punch 23 against the Thus, it will beunderstood that on any rework. At the start of this movement, the partswhen loading the press. However; as the plunger 22 starts downwardly andthe safety assembly is released, it falls ahead of the punch so that thefeeler device 42 moves to a position below the lower end of the punch.Also, as such safety device rocks about the pivots 35 and 45, theextension 53 of the arm 44 is rocked as fromthe position of Fig. 3 tothatof Fig. 6. As this occurs, the toe portion '54'of the slot 52 comesopposite thepin 5| and the wall portion 63 of said slot engages the pinand pressing on the latter, as the movement of the extension 53continues, forces the pin and thereby the cam 48 tomove in a clockwisedirection about the pivot 49 of the cam (during such movement, as thecam moves on its pivot, the pin 5| enters the slot portion 54) so thatthe cam is moved from its locking position of Fig. 3 to its releasedposition of Fig. 6.

In the former of these positions, it will be seen that the cam isprojecting into the path of movement of the lock blocl; -68 while inthe'latter of these positions the cam is wholly or substantially whollywithin the socket 41 and clear of the path of movement of the said lockblock. Thus, the lock block and therefore the plunger 22 may be given acomplete downward movement to have the punch 23 perform its desiredfunction. At this time, the feeler rod 4| is moved all the way down butsince there was no obstruction has not performed any function. Now, onrelease of the treadle 26, the plunger 22 is returned to its upper ornormal position and by: engagement of the surface or shoulder 59 of thelock block 68 with the pin 51 has brought about return movement of thevarious parts of the present safety device or guard.

The above describes the normal operation of the press or the operationof the press when the operator has been careful to keep his hands orfingers from any dangerous position with respect to the punch 23. Fig. 5illustrates what occurs when the operator carelessly or otherwise hashis fingers in a position to be injured. In such view, a portion of theoperators hand is suggested at 84. According to the disclosure in Fig.

5, the plunger '22 has started downwardly, the surface 59 of the lockblock 60 has moved downwardly from under the pin 51 and the variouselements of the present safety device (which elements include the arms36 and 44 and the carrier plate 38) have also started downwardly.However, the feeler 42 could not complete its downward movement andmoving ahead of the punch 23 has engaged the fingers of the hand 64. Itis to be borne in mind that this safety device including the feeler 42moves downwardly only under the influence of gravity. Thus, there is notenough weight or momentum to injure the operators hand or fingers.

arrested, the carrier plate 38 is held against'further downward movementand thus the arms 36 and 44 (and at this time we are particularlyconcerned with the latter) have had but limited movements about theirpivots 35 and 45, respectively. Since movement of the arm 44 has beenlimited, its extension 53 has had limited movement and has not movedsufiiciently to pick up the pin 5| and shift it and the cam 48 aboutthestill positioned with a portion of its arcuate surface 58 in the pathof movement of the arcuate surface 62 of the lock block and hasengagement Downward movement of the feeler having been I With suchlatter ,surtace. Therefore, the cam is presenting. a positive. lockpreventing movement of. the plunger 22 downwardly for any distancegreater than that illustrated. The distance between the arcuatesurfaces. 50' and 62, when the parts are in their upper positions ortheir normal positions, represents the length of. movement which'may beimparted to the punch 23 following'engagement of anobject by'the feelerdevice 42. Usually I'construct the parts so as to have downward movementof the punch: 23 stopped in about one quarter of :an inch of movementfollowing engagement of the fingers orthe like by the: feeler device 42.

When the. treadle is released with the parts positioned as in Fig. 5-,the plunger 22 is free to move upwardly and since it moves the lockblock 68, the latter will engage pin 51 and. the. parts of the presentsafety devicewill be carried upwardly. This has no particular efiectonthe cam-48 since the longpart or portion '55 of the slot 52 provides fora rocking movement of thearm 44 and its extension 55 on the pivot 45without any'binding against the pinil. The arcuate surfacesiD-and 62being complemental: or on equal length radii, there'ls no tendency forone to cam the other aside whenthey come into contact.

When the plunger has been given the full movement, assuggested in Fig.6, for the normal return of'the parts the surface. portion 85 of the toeportionil oi slotiz forcesthe pin 5| out of such toe portion. of theslot and into the long portion of the slot whereby the "extension 530ithe. arm 44, swingingon the pivot 45, doesnot' bind or in- .any waytightly engage with the pin 5|.

Having thus setv forth the nature of my invention, what I. claim is:

.1. In a machine, a stationary head and a plunger mounted on said headfor vertical reciprocating movement, .a lock platerigid with saidplungerand protecting at theiorward side of. said head, amounting plate on theforward side of saidhead-at one edge of said lock plate, said mountingplate having a notch opening through itsforward side and itsinne-r'edge, a cam, means pivotally mounting said cam for movementsbetween a position substantially wholly within saidnotch and out of theway of said lock plate and a. locking position projecting through theedge of'said'notch and into the path of movement of said lock plate, .acarrier plate movable vertically in a'plane forwardly of said lockplate,a pair of vertically spaced. parallel arms pivoted at their respectiveends to said mounting plate and carrier plate, a vertical feeler rod;means securing said feeler rod to said carrier plate for verticaladjustmentrelative thereto, a feeler means on the lowerend ofsaidfeelerrod, an extension-like part rigid with the upper of said arms: andhaving a slot therein including substantially right angularlyrelatedportions,,a pin rigid with said cam:in spaced relation to the .pivotalmounting'of the cam and'extending through the open side of said notchand through said slot, said parts related whereby when said upper arm isin its upper position said pin is in the first portion of said slot andsaid cam is projecting through the edge of said notch into the pathofdownward movement of. said locking plate to positivelylimit-downwardmovement of said plunger andwhereby when said upper arm is in its lowestposition said i'eeler' means is in its lowest position and saidextension like' part is positioned with said pin in thesecond portion ofwithin said notch and clear of the-path of downward movement of saidlocking plate, a stud rigid with the upper of said arms and movable withthe latter from av position'at a side of the path of movement; of saidlocking plate to a position in. such path and extending over theupperedge of the locking plate whereby as said plunger and plate-movedownwardly saidstud is released and said arms, carrier plate and feelerrodgravitate'downwardly as said arms turn about the means pivoting themto the mounting plate and said feeler means .moves ahead of the plunger,andas said plungerand plate move upwardly the upper edge of the plateengages said stud and moves the same upwardly moving said arms in theopposite'direction on their mentioned pivots and raising the'feeler rodand means.

2. In a machine, a stationary head and a plunger mounted on saidhead'for vertical reciprocating movement, :a lock plate rigid with saidplunger and projecting at the'forward side of said headya mounting plateon the'forward side o fisaid head. at one edge of said lock plate, saidmountingplate having a'notch opening through its forward side and itsinner-edge, a. cam, means pivotally' mounting saidcam. for movementsbetween a position substantially wholly within said notch and out of theWay of said lock plate and a loeking'position projjecting'through theedge of said notch and into the path of movement of said lock'plate, acarrier plate movable vertically in a plane. forwardly of said lockplate, a pair of vertically spaced parallel arms pivoted at :theirrespective ends'to said mounting plate andcarrier plate, a verticalfeeler'rod, means securing'said feeler rod to said carrier plate forvertical adjustment relative thereto, a feeler means. on the lower endof said feeler rod, an extension-like part rigid with the upper of saidarms and having a slot "therein including substantially right angularly'related portions, a pin rigid with said cam in spaced relation to thepivotal mounting of the. cam and extending through an open side of saidnotchand through said slot, said parts related wherebywhen said upperarm is in its upper position said pin is in the first portion of saidslot and said cam is projecting through the edge of said notch into thepath of downward movement of said locking plate to positively limitdownward movement of said plunger and whereby when said upper arm is inits lower position said feeler means is in its lower position andsaid-extension-like part is positioned with said pin in the secondportion of said'slot and said cam is substantially wholly within saidnotch and clear of the path' of downward movement of said locking-plate,a stud rigid with the upper of said arms and movable with the latterfrom a position'at a side of thepath of-movement of said locking plateto a position in such path and extending over the upper edge of thelocking plate whereby as said plunger and plate move downwardly saidstud is released and said arms, carrierplate and feeler rod gravitatedownwardly as said arms turnabout the means pivoting them to themounting plate and said feeler means moves ahead of the plunger, as saidplunger and plate move upwardly the upper edge of the plate engages saidstud and moves the same upwardly movingsaid arms in theoppositedirection on their mentioned pivots and-raising the feeler rod andmeans, and said feeler means adapted on engagement with an object duringdownward gravitational-movement of saidfeeler means to of said head, amounting plate on the forward side of said head at one edge of said lockplate, a cam, means pivotally mounting said cam on said mounting platefor movements between a position projecting into the path of downwardmovement of said lock plate and a position clear of such path ofmovement, a carrier plate movable vertically in a plane forwardly ofsaid lock plate, a pair of vertically spaced parallel arms pivoted attheir respective ends to said mounting plate and carrier plate, avertical feeler rod, means securing said feeler rod to said carrierplate for vertical adjustment relative thereto, a feeler means on thelower end of said feeler rod, an extension-like part rigid with theupper of said arms and having a slot therein including by When saidupper arm is in its lowest position said feeler means is in its lowestposition and said extension-like part is positioned with said pin in thesecond portion'of said slot and said cam is clear of the path ofdownward moveof said locking plate to a position in such path andextending over the upper edge of the locking plate whereby as saidplunger and plate move downwardly said stud is released and said arms,carrier plate and feeler rod gravitate downwardly as said arms turnabout the means pivoting them to the mounting plate and said feelermeans moves ahead of the plunger, and as said plunger and plate moveupwardly the upper edge of the plate engages said 'stud and moves thesame upwardly moving said arms in the opposite direction on theirmentioned pivots and raising the feeler rod and means.

4. In a machine, a stationary head and a plunger mounted on said headfor vertical reciprocating movement, a lock plate rigid with saidplunger and projecting at the forward side of said head, a mountingplate on the forward side of said head at one edge of said lock plate, acam, means pivotally mounting said cam on said mounting plate formovements between a position projecting into the path of downwardmovement of said lock plate and a position clear of such path ofmovement, a carrier plate movable vertically in a plane forwardly ofsaid lock plate, a pair of vertically spaced parallel arms pivoted attheir respective ends to said mounting plate and carrier plate, avertical feeler rod, means securing said feeler rOd to said carrierplate for vertical adjustment relative thereto, a feeler means on thelower end of said feeler rod, an extension-like part rigid with theupper of said arms and having a slot therein including substantiallyright angularly related portions, a pin rigid with said cam in spacedrelation to the pivotal mounting of the cam and extending through saidslot, said parts related whereby when said upper arm is in its upperposition said pin is in the first portion of said slot and said cam isprojecting into the path of downward movement of said locking plate topositively limit downward movement of said plunger and whereby when saidupper arm is in its lowest position said feeler means is in its lowestposition and said extension-like part is positioned with said pin in thesecond porton of said slot and said cam is clear of the path of downwardmovement-of saidlocking plate, a stud rigid with the upper of said armsand projecting rearwardly therefrom into the path of movement ofsaid'lock plate whereby on upward movement of said plunger said stud isengaged by said plate and said carrier plate, arms and said feeler rodare moved upwardly as said arms swing on their pivotal mountings on themounting plate. and whereby on downward movement of the plunger saidstud is released and said arms and carrier plate gravitate downwardly assaid arms pivot in the opposite direction, and said feeler means adapted0n engagement with an object during downward movement of said feelermeans to act through said feeler rod and maintain said carrier plate andarms against further movement in a direction to have the extension-likepart of the upper arm move to receive the pin in the second portion ofsaid slot whereby said plunger is locked against all but limiteddownward movement.

5. In a machine, a stationary head and a plunger mounted on said headfor vertical reciprocating movement, a lock plate rigid with saidplunger and projecting at the forward side of said head, a mountingplate on the forward side of said head at one edge of said lock plate, acam, means pivotally mounting said cam on said mounting plate formovements between a position projecting into the path of downwardmovement of said lock plate and a position clear of such path ofmovement, a carrier plate movable vertically in a plane forwardly ofsaid lock plate, a pair of vertically spaced parallel arms pivoted attheir respective ends to said mounting plate and carrier plate, avertical feeler rod, means securing said feeler rod to said carrierplate for vertical adjustment relative thereto, a feeler means on thelower end of said feeler rod, an extension-like part rigid with theupper of said arms and having a slot therein including sub stantiallyright angularly related portions, a pin rigid with said cam in spacedrelation to the pivotal mounting of the cam and extending through saidslot, said parts related whereby when said upper arm is in its upperposition said pin is in the first portion of said slot and said cam isprojecting into the path of downward movement of said locking plate topositively limit downward movement of said plunger and whereby when saidupper arm is in its lowest position said feeler means is in its lowestposition and said extension-like part is positioned with said pin in thesecond portion of said slot and said cam is clear of the path ofdownward movement of said locking plate, means whereby on its upwardmovement said plunger moves said arms, carrier plate and feeler meansupwardly swinging said arms on their pivotal connections with themounting plate and whereby on downward movement of the plunger saidarms, carrier plate and feeler means are released to gravitatedownwardly as said arms swing in the opposite direction, 'and'saidi'eeler means adapted on engagement with an object during downwardmovement ofw-said f'eeler means to act through said feeler rod andmaintain said carrier plate and arms against further movement in adirection to have theextension-liike part of the upper-arm move" toreceive the pin in the second portion of said slot.

6. In a machine, a stationary head and a plunger mounted said head forvertical reciprocating movement, a lock plate rigid with said plungerand projecting at the forward side of said head, a mounting plate on theforward side of said head at o'needge of said lock plate, said mountingplate having a notch opening through its forward side and its inneredge, a cam, means pivotally' mounting said cam for movements between aposition substantially wholly within said notch and out of the way ofsaid lock plate and alocking position projecting through the edge ofsaid notch and into the path of movement of said lock plate, a carrierplate movahly vertically in a plane forwardly-of said lock plate, a pairof vertically-spaced parallel arms pivoted at their res'pe'ctive ends tosaid mounting plate and carrierplate, a vertical feeler rod, meanssecuring said feeler rod' to said carrier plate for vertica-l'adjustmentrelative thereto, a feeler means on the lower end of said feeler rod, anextension-like partrigidwith i the upper of said arms and having a slottherein including substantially right angularly related portions, a-piri'ri'gid with said cam in spaced relatibn to the pivotal mounting of thecam and extending through the open side of said notch and throug-h'saidslot, said parts related whereby when saidupper arm is in its upperposition-said pin is in the first portion of said slot and said cam isprojecting through the edge-of said notch into the path of downwardmovement of said locking plate to positively limit downward movement ofsaid-plunger and whereby when said upper arm is in its lowest positionsaid'feeler means is in its lowest position and said extension-like partis positioned with said pin in the second portion of said slotand saidcam is substantially wholly withinsaid notch and clear of the path ofdownward movement of said locking plate, cooperating means between saidplunger and one of said arms for raising said arms and carrier plate byswinging the arms on their pivotedconnections with the mounting plate assaid plunger is moved upwardly in said head, said means adapted torelease said parts as said plunger moves downwardly in-said head, andsaid parts adapted on release to gravitate downwardly whereby on saidfeeler .means engaging an obstruction further downward gravitationalmovement of said parts 12 is pie've-ntexlandsaid cam remains' in thefirst mentioned position and said plunger is locked against all butlimited downward movement in said'head.

'7. In a machine, a stationary head and a plunger mounted on said headforverticalreciprocating movement-a lock plate rigid with said plunger,a mountingv plate on said head, a cam, means pivotallymounting said camon said mounting plate for movements between a position projectinginto'the path of downward :movement of said lockplate" and a positionclear of such path of movement, a 'c'arrierplate movable vertically inasingle plane, a pair of vertically spaced parallel arms pivoted attheir respective ends to said mounting plate and carrierplate, avertical f'eeler, means securing said feeler to said carrierplate forvertical reciprocating movement therewith, an extension-like part rigidwith one of said arms and having a slot therein includingzsubstantiallyright angularlyrel'ated'portions, a, pin rigid with said cam in spacedrelation to the pivotal mounting of the cam and extending through saidslot, said parts related whereby. when said one arm-is in" its upperposition said pin is in the firstflporti'o'n of saidslot and said camisprojecting-into the path of downward movementofssaid locking plate topositively limitdownward movement of said plunger and whereby when saidone ar-mis in its lowest position said reeler is in itslowestpositionhmd'asaid extension-like part is positioned'iwith saidpinin-the second portion of said slot andsaid oa'm is clear or the path ofdownwardnmovement of said look- .ing plate, means whereby on its upwardmovementsaid plunger movesisaid arms; carrier plate and feeler meansupwardly swinging said arms on their pivotal connections withthemounting plate and whereby ondownward movement of the plunger said arms,carrier plate and feele'riar'e released to gravitate downwardly :as :said arms swing in the opposite direction, andsaidfeeler adapted onengagement with aIlFObQiEdt during downward movement *of said reeler tosaid, carrier ,plate and armszagainst rfurtherzmovement in a directionto have the extensiion-like part of said onearm move toareceive'the pinin the second portionof said slot:

GEORGE Number I Date .inoaioc July 28-, 1914 2,049,990 Armstrong;- .Aug.4; 1936.

